In checking out issues regarding public domain, I have discovered that you must check out the specifics of a property to find out of it is still covered by copyright.

Case in point, the Happy Birthday song; created in 1893 but first copyrighted in 1935. In 1935 there was no automatic copyright upon creation, and the youngest of the three Hill sisters registered her older sisters song because she was then working for a music publisher and knew something about the laws.

With renewals and changes in copyright law over time, notably 1978 and 1989, the Happy Birthday song still has an active copyright (Warner-Chappell) and still makes the copyright holder over $2million a year.

So the short of it is, you have to check and just because something was created prior to 1927 does not automatically mean it is in the public domain.